Occlusion of blood vessels is desired in a number of clinical situations. For example, vascular embolization has been used to control vascular bleeding, to occlude the blood supply to tumors, and to occlude vascular aneurysms, particularly intracranial aneurysms. For example, vascular embolization may be used to occlude or close off the vessels that are supplying blood to a tumor, especially when the tumor is difficult or impossible to remove. Following embolization, a tumor may shrink or it may continue to grow but more slowly, making chemotherapy or surgery a more effective option.
Embolization procedures may utilize a variety of embolic agents, including coils, foams, glues, or ethanol. Embolization coils are typically made of stainless steel and/or platinum, often in conjunction with vascular obstruction devices, including “spider” devices to prevent dislodgment of embolization coils beyond the site of delivery. A problem with these devices is that it takes time to occlude the vessel and often leaves beyond foreign, stainless steel materials in the body. Also, this arrangement is more complex because it may require the delivery of two separate devices to the vasculature. Another approach involves the direct injection of liquid, semi-solid, or solid occlusion agents, including sponge-like or foam plugs into target vessel sites. However, the performance of these agents and other related approaches suffer from problems of migration and difficulties of retrievability, when necessary.
Accordingly, there exists a need for improved vascular plug devices that can rapidly occlude a body vessel and become anchored thereto and that can promote cellular ingrowth and permanently integrate into the body tissues.